Given this pathogenesis, we postulate that CML is an incidental diagnosis rather than related to FD/MAS pathogenesis, as MAS involves the increased activation of the cyclic AMP-protein kinase signal transduction pathway, from the somatic gain of mutation in the GNAS gene on chromosome 20q13-13.29.3 Here, GNAS is linked to chronic myelogenous leukemia, BCR-ABL1 positive.